Ti对AlFeCrCoCu高熵合金组织及耐磨性能的影响

Effect of Ti Addition on the Microstructure and Wear Properties of AlFeCrCoCu High-Entropy Alloy

研究了非自耗电弧熔炼AlFeCrCoCu,AlFeCrCoCuTi高熵合金以及AlFeCrCoCuTi合金800℃回火后的组织、硬度及耐磨性能。研究发现,相比于AlFeCrCoCu合金,AlFeCrCoCuTi合金组织结构趋于复杂,合金由简单的bcc+fcc相变为由bcc1相,bcc2相,fcc相以及析出ω相组成的4相固溶体。Ti的加入提升了合金的整体硬度。合金具有很强的抗回火软化能力。3组合金的摩擦磨损主要以黏着磨损为主。Ti的添加,导致析出相的析出强化效应以及枝晶两相共析组织的特殊结构,提高了合金的耐磨性能。而回火后的AlFeCrCoCuTi合金耐磨性能更优,主要原因是随着摩擦时间的增加,回火后的合金表面上生成了一层氧化物附着在摩擦表面,提高了合金的耐磨性能。

The microstructures of AlFeCrCoCu,AlFeCrCoCuTi and 800 °C tempered AlFeCrCoCuTi high-entropy alloys fabricated by an arc remelter were investigated by XRD, SEM, EDS and DSC. The alloys’ hardness and wear properties were also tested. The results show that AlFeCrCoCu alloy possesses face-centered cubic（fcc） and body-centered cubic（bcc） phases. After the addition of titanium,AlFeCrCoCuTi alloy is composed of primary dendrite phase（The β phase rich in Al, Co, Ti and the α phase rich in Fe, Cr eutectoid structure）, interdendrite phase rich in Cu and the precipitated phase rich in Cr. Meanwhile, the hardness of AlFeCrCoCuTi alloy increases.AlFeCrCoCuTi alloy exhibits a superior resistance to tempering and softening. The wear of the three alloys is adhesive wear, while the wear resistance of the Al Fe Cr Co Cu Ti alloy improves, and the wear resistance of 800 °C tempered AlFeCrCoCuTi alloy is better than that of as-cast alloys. The main reason is that with the increase of friction time, the 800 °C tempered AlFeCrCoCuTi alloy generates a layer of oxide on the surface and it attaches to the friction surface, thus improving the wear resistance of the alloy.